textproduct: Albany

WHAT HAS CHANGED

Slight risk ERO for Sunday has been largely removed from the NWS Albany forecast area. While we are still expecting widespread rain Sunday, flash flooding does not appear to be a concern for our forecast area.

KEY MESSAGES

1) Dry and cool weather returns today into tomorrow.

2) An area of low pressure will bring widespread rain to the region Sunday, followed by drier but cool weather for the first half of next week.

DISCUSSION

KEY MESSAGE 1...As of 2:50 AM EDT...Current sfc analysis shows the weak sfc low that brought showers yesterday departing well to our east. A trailing cold front is draped across the Mid Hudson Valley, with a second, stronger front approaching NY and the eastern Great Lakes from southern Canada. Ahead of this second front, abundant low-level moisture is leading to plenty of fog and low stratus. Dew points are also in the 60s, which is keeping temperatures quite warm for mid September. Overnight lows will range from 50s (high terrain) to mid 60s (valleys).

Once the secondary cold front moves through this morning, the low clouds and fog should quickly mix out, with skies becoming partly to mostly clear. It will end up being a very pleasant day, with highs in the 60s (terrain) to mid 70s (valleys), lowering humidity, and breezy N/NW winds. Winds diminish tonight as a 1028+ mb sfc high builds into southern Canada. Temperatures will drop into the 30s (terrain) to 40s (valleys). Despite the dry airmass, some patchy fog will be possible in the typical river valleys and near wetlands. With the ADKs being closest to the center of the sfc high, favorable radiational cooling conditions may allow for some patchy frost to develop in the sheltered areas, but coverage is not expected to be widespread enough to warrant frost advisory issuance.

Tomorrow, the sfc high slides overhead. There will be some mid and high clouds around, but it should be a very nice early-fall day with highs mainly in the 60s and continued low humidity.

KEY MESSAGE 2... Late Saturday night into Sunday, a sfc low will develop in response to an upper impulse and track along a stalled frontal boundary from the Ohio Valley towards/just south of our region. A strengthening LLJ will aid in transporting moisture northwards into our region. While the sfc warm front remains to our south, strong mid-level warm advection/isentropic lift/FGEN and the right entrance region of an upper jet streak to our north will provide plenty of forcing for ascent, so we are expecting widespread rain and showers late Saturday night and Sunday. The heaviest rain will fall across southern areas where the best mid-level forcing will be. Total rainfall amounts generally look to be 0.25 to 0.75" north of I-90, with 0.75 to 1.5" south, except near I-84 where some higher amounts up to around 2" will be possible. Given that 1-hr FFG values are generally >2", rain will be stratiform in nature, and little to no instability, we collaborated with neighboring WFOs and WPC to have the slight risk ERO trimmed back. However, even the northern extent of the marginal risk ERO still seems too bullish. While some nuisance ponding of water in the typical low-lying and poor drainage areas is possible, the bottom line is that the probability of any flash flooding in the ALY CWA is very, very low at this time. Due to widespread rain/wetbulbing, highs Sunday may not make it out of the 50s for many areas.

Showers should come to an end Sunday night as a strengthening sfc high builds into southeastern Canada beneath confluent upper flow. This will help push the frontal boundary back south, so Monday looks relatively dry at this time. For Tuesday through the middle of next week, there is some uncertainty if the sfc high will continue to suppress this boundary to our south or if the sfc high will retreat enough that the boundary is able to lift north and bring some renewed shower chances to our southern areas. Given the strength of the sfc high, we are leaning towards the drier solution. With our area expected to be on the cool side of the frontal boundary, temps should remain below normal with highs in the 50s (terrain) to 60s (elsewhere) and lows in the upper 30s to 40s each day/night.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

Through 12z Saturday...As of 6:20 AM EDT, still seeing some IFR to LIFR vsbys and cigs at GFL/POU/PSF with fog/mist/low stratus, while ALB is seeing MVFR stratus. Fog/mist/low stratus may linger through the next hour or two, but should lift and mix out fairly quickly after 12z this morning as drier air works into the region behind a cold front and winds pick up from the N/NW. By mid-morning, just expecting SCT mid-level clouds with a return to VFR conditions across the board. VFR conditions with FEW to SCT mid-level clouds 4000-6000 ft prevail through this evening, with mid clouds diminishing after sunset. With a light wind and increasing high clouds tonight, have opted not to include any fog/mist at this time, but it can't totally be ruled out at GFL/PSF. Will evaluate with future TAF issuances and see if this needs to be added.

Light winds pick up to 5-10 kt from the N/NW around or shortly after 12z, increasing to around 10 kt with gusts to 20 kt from mid-morning through sunset this evening. Light northerly winds then expected through the rest of the night.

Outlook...

Saturday Night: Moderate Operational Impact. Chance of SHRA. Sunday: High Operational Impact. Definite RA. Sunday Night: High Operational Impact. Likely SHRA...RA. Monday: Low Operational Impact. NO SIG WX. Monday Night: Moderate Operational Impact. Chance of SHRA. Tuesday: Moderate Operational Impact. Chance of SHRA. Tuesday Night: Low Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.